What features do you actually use in freelancing apps?

Most apps have long feature lists, but freelancers usually stick to 2–3 things that really matter. I’m trying to get a clearer picture as I build Ativium Freelancing.

What do you personally rely on the most?
Tasks? Invoicing? Client notes? Something else?

Trying to build something practical, not bloated — would love your perspective.
https://ativium-freelancing.com